The presence of moisture on the leaves of legumes caused by rainfall, dew of guttation makes combined harvesting of the crop difficult. This problem is particularly serious with Black-eye pea (Vigna sinensis). The Black-eye pea plant forms a canopy which remains green and healthy even up to the time the mature yellow and/or dry pods are ready for harvesting. The presence of moisture on the living plant makes mechanical harvesting difficult and crop losses are particularly heavy. Defoliation and/or desiccation of the foliage using mineral spray oils would preclude moisture formation on the leaves thus facilitating mechanical harvesting of the crop.